The neighboring Anishanabeg Ojibwe (Sauk name: Ochipwêwa) and Odawa peoples referred to them by the exonym Ozaagii(-wag), meaning "those at the outlet".

This interpretation possibly derived from the Sauk words Athâwethiwa or Athâw(i) ("yellow")[2] and Neniwaki ("men, people").

They had been driven west by pressure from other tribes, especially the powerful Haudenosaunee, which sought control over hunting grounds in the area.

[5] In this battle, it is said that the Sauk had used their boats to cross part of the river, escape to the island, and were temporarily free from their attackers.

In a loose coalition of tribes – including Dakota (Ashâha), Ho-Chunk, Ojibwe, Odawa, Potawatomi, Kickapoo (Kîkâpôwa), Meskwaki (Fox), and Sauk, along with the Shawnee (Shâwanôwa), Cherokee (Shanahkîha), and Choctaw (Châkitâha) from the Southeast – they attacked the tribes of the Illinois Confederation (Mashkotêwa) and tried to invade their tribal areas.

At first, the Sauk had good relations with New France too, until their alliance with the Meskwaki (Fox) made them short-term enemies of the French (Mêmehtekôshîha, Wêmehtekôshîha).

A closely allied tribe, the Meskwaki (Fox), were noted for resisting French encroachment, having fought two wars against them in the early 18th century.

After a devastating battle of September 9, 1730, in Illinois, in which hundreds of warriors were killed and many women and children taken captive by French allies, Fox refugees took shelter with the Sac.

At first, Keokuk accepted the loss of land as inevitable in the face of the vast numbers of white soldiers and settlers coming west.

Having failed to receive expected supplies from the Americans on credit, Black Hawk wanted to fight, saying his people were "forced into war by being deceived".

[7] Led by Black Hawk in 1832, the mainly Sac band resisted the continued loss of lands (in western Illinois, this time.)

Their warfare with United States forces resulted in defeat at the hands of General Edmund P. Gaines in the Black Hawk War.

From 1832 to 1837, debt and poverty were tools used to coerce the Sauk and Meskwaki to relocate three times following successive cessions of territory.

In 1887, however, the Dawes Act purposely broke collective tribal lands into small allotments designated for individual households.

The remainder of land not allotted to the Sac and Fox was then sold to non-Native settlers in an attempt to gain Oklahoma statehood and the full assimilation of its Native American population.

The Sauk and Fox peoples were divided into two moieties or "divisions", which in turn were subdivided into Patri-lineages and Clans as local subgroups (segments).

This duality was also celebrated by the two moieties in Lacrosse, which was often played extremely brutally to toughen young warriors for combat, for recreation, as part of festivals, and used as preparation for imminent wars or raids.

[9] Saukenuk or Saukietown (today: Black Hawk State Historic Site) near the mouth of the Rock River (Sinnissippi – "rocky waters") into the Mississippi (Mäse'sibowi – "great river"),[10] the most important Sauk settlement in the 18th and 19th centuries with about 4,000 inhabitants, was divided into 12 districts, which were assigned to the respective clans.

This traditional manner of selecting historic clan chiefs and governance was replaced in the 19th century by the United States appointing leaders through their agents at the Sac and Fox Agency, or reservation in Indian Territory (now Oklahoma).